2 * atmel-pcm-dma.c -- ALSA PCM DMA support for the Atmel SoC.
4 * Copyright (C) 2012 Atmel
6 * Author: Bo Shen <voice.shen@atmel.com>
8 * Based on atmel-pcm by:
9 * Sedji Gaouaou <sedji.gaouaou@atmel.com>
10 * Copyright 2008 Atmel
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/platform_device.h>
30 #include <linux/slab.h>
31 #include <linux/dma-mapping.h>
32 #include <linux/dmaengine.h>
33 #include <linux/atmel-ssc.h>
34 #include <linux/platform_data/dma-atmel.h>
36 #include <sound/core.h>
37 #include <sound/pcm.h>
38 #include <sound/pcm_params.h>
39 #include <sound/soc.h>
40 #include <sound/dmaengine_pcm.h>
42 #include "atmel-pcm.h"
44 /*--------------------------------------------------------------------------*\
46 \*--------------------------------------------------------------------------*/
47 static const struct snd_pcm_hardware atmel_pcm_dma_hardware
= {
48 .info
= SNDRV_PCM_INFO_MMAP
|
49 SNDRV_PCM_INFO_MMAP_VALID
|
50 SNDRV_PCM_INFO_INTERLEAVED
|
51 SNDRV_PCM_INFO_RESUME
|
53 .formats
= SNDRV_PCM_FMTBIT_S16_LE
,
54 .period_bytes_min
= 256, /* lighting DMA overhead */
55 .period_bytes_max
= 2 * 0xffff, /* if 2 bytes format */
57 .periods_max
= 1024, /* no limit */
58 .buffer_bytes_max
= ATMEL_SSC_DMABUF_SIZE
,
62 * atmel_pcm_dma_irq: SSC interrupt handler for DMAENGINE enabled SSC
64 * We use DMAENGINE to send/receive data to/from SSC so this ISR is only to
65 * check if any overrun occured.
67 static void atmel_pcm_dma_irq(u32 ssc_sr
,
68 struct snd_pcm_substream
*substream
)
70 struct snd_soc_pcm_runtime
*rtd
= substream
->private_data
;
71 struct atmel_pcm_dma_params
*prtd
;
73 prtd
= snd_soc_dai_get_dma_data(rtd
->cpu_dai
, substream
);
75 if (ssc_sr
& prtd
->mask
->ssc_error
) {
76 if (snd_pcm_running(substream
))
77 pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x)\n",
78 substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
79 ? "underrun" : "overrun", prtd
->name
,
82 /* stop RX and capture: will be enabled again at restart */
83 ssc_writex(prtd
->ssc
->regs
, SSC_CR
, prtd
->mask
->ssc_disable
);
84 snd_pcm_stop(substream
, SNDRV_PCM_STATE_XRUN
);
86 /* now drain RHR and read status to remove xrun condition */
87 ssc_readx(prtd
->ssc
->regs
, SSC_RHR
);
88 ssc_readx(prtd
->ssc
->regs
, SSC_SR
);
92 /*--------------------------------------------------------------------------*\
93 * DMAENGINE operations
94 \*--------------------------------------------------------------------------*/
95 static bool filter(struct dma_chan
*chan
, void *slave
)
97 struct at_dma_slave
*sl
= slave
;
99 if (sl
->dma_dev
== chan
->device
->dev
) {
107 static int atmel_pcm_configure_dma(struct snd_pcm_substream
*substream
,
108 struct snd_pcm_hw_params
*params
, struct atmel_pcm_dma_params
*prtd
)
110 struct ssc_device
*ssc
;
111 struct dma_chan
*dma_chan
;
112 struct dma_slave_config slave_config
;
117 ret
= snd_hwparams_to_dma_slave_config(substream
, params
,
120 pr_err("atmel-pcm: hwparams to dma slave configure failed\n");
124 if (substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
) {
125 slave_config
.dst_addr
= (dma_addr_t
)ssc
->phybase
+ SSC_THR
;
126 slave_config
.dst_maxburst
= 1;
128 slave_config
.src_addr
= (dma_addr_t
)ssc
->phybase
+ SSC_RHR
;
129 slave_config
.src_maxburst
= 1;
132 dma_chan
= snd_dmaengine_pcm_get_chan(substream
);
133 if (dmaengine_slave_config(dma_chan
, &slave_config
)) {
134 pr_err("atmel-pcm: failed to configure dma channel\n");
142 static int atmel_pcm_hw_params(struct snd_pcm_substream
*substream
,
143 struct snd_pcm_hw_params
*params
)
145 struct snd_soc_pcm_runtime
*rtd
= substream
->private_data
;
146 struct atmel_pcm_dma_params
*prtd
;
147 struct ssc_device
*ssc
;
148 struct at_dma_slave
*sdata
= NULL
;
151 snd_pcm_set_runtime_buffer(substream
, &substream
->dma_buffer
);
153 prtd
= snd_soc_dai_get_dma_data(rtd
->cpu_dai
, substream
);
156 sdata
= ssc
->pdev
->dev
.platform_data
;
158 ret
= snd_dmaengine_pcm_open_request_chan(substream
, filter
, sdata
);
160 pr_err("atmel-pcm: dmaengine pcm open failed\n");
164 ret
= atmel_pcm_configure_dma(substream
, params
, prtd
);
166 pr_err("atmel-pcm: failed to configure dmai\n");
170 prtd
->dma_intr_handler
= atmel_pcm_dma_irq
;
174 snd_dmaengine_pcm_close_release_chan(substream
);
178 static int atmel_pcm_dma_prepare(struct snd_pcm_substream
*substream
)
180 struct snd_soc_pcm_runtime
*rtd
= substream
->private_data
;
181 struct atmel_pcm_dma_params
*prtd
;
183 prtd
= snd_soc_dai_get_dma_data(rtd
->cpu_dai
, substream
);
185 ssc_writex(prtd
->ssc
->regs
, SSC_IER
, prtd
->mask
->ssc_error
);
186 ssc_writex(prtd
->ssc
->regs
, SSC_CR
, prtd
->mask
->ssc_enable
);
191 static int atmel_pcm_open(struct snd_pcm_substream
*substream
)
193 snd_soc_set_runtime_hwparams(substream
, &atmel_pcm_dma_hardware
);
198 static struct snd_pcm_ops atmel_pcm_ops
= {
199 .open
= atmel_pcm_open
,
200 .close
= snd_dmaengine_pcm_close_release_chan
,
201 .ioctl
= snd_pcm_lib_ioctl
,
202 .hw_params
= atmel_pcm_hw_params
,
203 .prepare
= atmel_pcm_dma_prepare
,
204 .trigger
= snd_dmaengine_pcm_trigger
,
205 .pointer
= snd_dmaengine_pcm_pointer_no_residue
,
206 .mmap
= atmel_pcm_mmap
,
209 static struct snd_soc_platform_driver atmel_soc_platform
= {
210 .ops
= &atmel_pcm_ops
,
211 .pcm_new
= atmel_pcm_new
,
212 .pcm_free
= atmel_pcm_free
,
215 int atmel_pcm_dma_platform_register(struct device
*dev
)
217 return snd_soc_register_platform(dev
, &atmel_soc_platform
);
219 EXPORT_SYMBOL(atmel_pcm_dma_platform_register
);
221 void atmel_pcm_dma_platform_unregister(struct device
*dev
)
223 snd_soc_unregister_platform(dev
);
225 EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister
);
227 MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
228 MODULE_DESCRIPTION("Atmel DMA based PCM module");
229 MODULE_LICENSE("GPL");